cvs commit: src/sys/boot/i386/mbr Makefile mbr.s

[John Baldwin]

On Tuesday 31 August 2004 01:08 am, Yar Tikhiy wrote:
> On Mon, Aug 30, 2004 at 11:41:00AM -0400, John Baldwin wrote:
> > On Saturday 28 August 2004 04:39 am, Yar Tikhiy wrote:
> > > yar         2004-08-28 08:39:35 UTC
> > >
> > >   FreeBSD src repository
> > >
> > >   Modified files:
> > >     sys/boot/i386/mbr    Makefile mbr.s
> > >   Log:
> > >   Don't be too smart, just try packet mode of INT13 first.
> > >   This way of operation is more robust than the "AI" used
> > >   before.
> > >
> > >   Add flags to mbr accessible from make.conf as BOOT_MBR_FLAGS.
> > >   Only one flag is defined now, "allow using packet mode", which
> > >   is 0x80 in accord with the rest of i386 boot code.  The "packet"
> > >   flag is on by default.
> > >
> > >   PR:             i386/70241
> > >   Submitted by:   Valentin Nechayev <netch <@> netch.kiev.ua> (inital
> > > version) Discussed with: jhb (by Valentin Nechayev)
> > >   Tested on:      bochs (with EDD turned on or off by patching the
> > > BIOS), PCs
> > >
> > >   Revision  Changes    Path
> > >   1.14      +4 -0      src/sys/boot/i386/mbr/Makefile
> > >   1.7       +6 -6      src/sys/boot/i386/mbr/mbr.s
> >
> > Hmm, there are no e-mails from me in the PR trail and I don't recall ever
> > be in favor of these changes (though I don't care enough to ask for them
> > to be backed out..  Only really old machines with pre-1995 BIOS should be
> > broken in theory.)  It would be nice if you wouldn't claim that I
> > supported something that I didn't actually support though.
>
> John, I try to believe people as much as possible since that saves
> my time, and I believe Valentin Nechayev particularly because I know
> him quite well.  Here are his words straight from the PR:
>
> %%%
>
> >Fix:
>
> Revert logic of selection between traditional and EDD reading mode
> to one which prefers EDD if available (as was in the same file in revisions
> 1.11 and 1.12). This is supported by John Baldwin (private conversation
> after thread in hackers@):
> ==={{{
> The problem is that there are BIOS's out there that claim to support EDD
> but still don't work correctly.  I don't remember all the details at this
> point, but I think it had to do with sysinstall not always being in sync
> with the BIOS about how sectors were in a cylinder.  I guess though we
> could just turn EDD on by default in 5.x or perhaps 6.0.  5.x doesn't
> really run well on a 386 or even a 486, and that is the class of machine
> that has problems with EDD.
> ===}}}
>
> %%%
>
> I know it could be hard on memory to return to issues one used to
> work at in the past, so I decided not to bother you to confirm if
> that quote is actually yours.  Please excuse me if it was a poor
> idea of mine.

Hmm, maybe my memory is worse.  I found some e-mails in my archive when I 
searched but not this one.  The quoted e-mail above is mine and is correct.  
I guess I kind of forgot that this was a 6.0 change and 6.0 won't be out for 
a while.  My apologies for getting all jumpy.

-- 
John Baldwin <jhb at FreeBSD.org>  <><  http://www.FreeBSD.org/~jhb/
"Power Users Use the Power to Serve"  =  http://www.FreeBSD.org